At the end of the 1940s, L Ron Hubbard – a sinophobic college dropout turned pulp writer (his pseudonyms included Joe Blitz and Legionnaire 148) turned reckless naval officer (one report claimed he was “lacking in the essential qualities of judgment, leadership and co-operation”) turned ulcerous and gonorrhea-afflicted war veteran – hatched a plan to revive his stuttering fortunes. “I’d like to start a religion,” he’s reported to have declared. “That’s where the money is.”

Going Clear, Lawrence Wright‘s new study of the man and his followers, shows just how right he was. By 1950, Hubbard had developed a self-help system called dianetics, which was to form the basis of the Church of Scientology, whose assets are now reputed to be in the order of £1bn. Yet, though it claims a membership of 8m worldwide, independent studies suggest only 30,000 Americans call themselves Scientologists: that’s less than half the number of Americans who identify as Rastafarian.

The line between fact and fiction, objective reality and fevered speculation, has always been foggy when it comes to Scientology. That’s partly because of Hubbard and the weird eschatologies he devised, which involved a despotic leader named Xenu and billions of spirit-like creatures called thetans who were transported to Earth only to be dropped into volcanoes before being blown up by hydrogen bombs.

It’s also a result of the litigious and bullying tactics of church members, who scare off would-be investigators (to the point that Wright’s book can’t be published in the UK). And perhaps it’s something to do with our desire for a narrative – equal parts Hollywood Babylon, ufology and David Koresh-style cult – that couches postwar American history, especially the gulf between its sunny side-up rhetoric and its rather glummer social polity, as one big conspiracy theory.

The Hubbard that emerges from Going Clear is certainly no saint. He’s a serial cheat, an abusive husband who kidnapped one of his daughters from an early wife and claimed to have “cut her into little pieces and dropped the pieces in a river”, an increasingly sybaritic ideologue who believed America’s jails and mental hospitals were full of inmates who had been unsuccessfully aborted by their “sex-blocked mothers to whom children are a curse, not a blessing of God”.

But Hubbard, even though he lived in a country estate in Sussex in the early 60s, and dreamed of taking over Rhodesia, is also the embodiment of a peculiar and not unimpressive kind of American dynamism: a Barnum-like huckster, confidence man as philosopher, the quack who would be king. That will-to-power – as epic in its ambition as the tales in the science fiction journals where his theories were first elaborated – is also evident in the world’s most famous modern-day Scientologist, Tom Cruise, who is reported here as saying: “If fucking Arnold can be governor, I could be president.” (The book records Cruise’s denial that he ever said this.)

Going Clear has been eagerly awaited following the Pulitzer prize-winning Wright’s 2011 New Yorker article about the church, which drew heavily on the testimony of Academy award-winning film-maker Paul (Crash) Haggis, a former Scientologist and father of two lesbian daughters who later recoiled from the church’s anti-gay theories. The book is diligently researched, calmly expository, and full of fascinating side-stories (most readers will be unaware of Hubbard’s fondness for the teachings of English occultist Aleister Crowley or his influence on the writings of William Burroughs).

Over the past week American bloggers have been exultantly cherrypicking it for bizarre episodes and tut-tutting over Hubbard’s apparent reaction to the early death of his son Quentin: “That little shit has done it to me again.” Particularly disturbing is Wright’s description of a darkened basement in a Scientology building where difficult members and their children were holed up.